TOKYO - President Obama said Thursday that he wants to see a dispute between China and Japan over islands in the East China Sea resolved peacefully, while affirming that America's mutual security treaty with Japan applies to the islands.

"Historically, they have been administered by Japan and we do not believe that they should be subject to change unilaterally," Obama said at a news conference with Prime Minister Shinzo Abe. "What is a consistent part of the alliance is that the treaty covers all territories administered by Japan."

China and Japan have conflicting claims to the remote islands, called Senkaku by Japan and Diaoyu by China. The dispute has badly strained relations between the two Asian powers.

A U.S.-Japan defense treaty requires Washington to come to Japan's defense if it is attacked. Obama said his defense of that treaty is not a new position.

"The treaty between the U.S. and Japan preceded my birth, so obviously this isn't the red line that I'm drawing," the president said.

A Chinese government spokesman has said China has "indisputable sovereignty" over the islands and that "the so-called Japan-U.S. alliance" should not harm China's territorial rights.

Obama said he wants the maritime issue to be worked out "through dialogue." He urged the two sides to "keep the rhetoric low."

"It would be a profound mistake to continue to see escalation around this issue instead of dialogue," Obama said he told Abe during a private meeting.

While China is not on Obama's eight-day itinerary in Asia, leaders in Beijing are closely watching the president's tour. Obama's advisers insist that the trip - and the White House's broader Asia policy - are not designed to counter China's growing power, and they say the president is not asking Asian nations to choose between allegiance to Washington or Beijing. "We want to continue to encourage the peaceful rise of China," Obama said.

Abe said he and Obama agreed to cooperate on engagement with China, along with other topics, including a stalled trans-Pacific trade agreement and the impact of the U.S. military presence in Okinawa.

"The Japan-U.S. alliance is more robust than ever before," Abe said.

On another Asian concern, Obama said he's not optimistic that North Korea will change its behavior in the near future. But he said he's confident that by working with Japan, South Korea and others, the U.S. can apply more pressure so that "at some juncture, they end up taking a different course."